code: def test_image_update():
      fig = plt.figure(dpi=100)
      ax = plt.subplot(111)
      da = dsshow(df, ds.Point("x", "y"), ax=ax)
      ax.set_xlim(0, 0.5)
      ax.set_ylim(0, 0.5)
      fig.canvas.draw()
  
      data = da.get_ds_data()
      assert data[0, 0] == 5
      assert data[0, -1] == 0
      assert data[-1, 0] == 0
      assert data[-1, -1] == 0
  
file_path: datashader/datashader/tests/test_mpl_ext.py
imports: from __future__ import annotations
  import pytest
  import matplotlib
  import matplotlib.pyplot
  import numpy
  import pandas
  import datashader
  from datashader.mpl_ext import dsshow
label_desc: Use image node_id 2 for calling a global function with example usage: test_image_update() without return types